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A. E. BRIGGS. Magneto Electrical Machines.

Patented Aprl13,1880.

HTP/e N. PETERS. PHOTO-LITHDGRAFHER. wAsHlNGToN. DvC,

' UNITED STATES PATENT OFFICE.

ARTHUR E. BRIGGS, OF CINCINNATI, OHIO, ASSIGNOR TO POST CO., OF

' SAME PLACE.

MAGNETO-ELECTRICAL. MACHINE.

SPECIFICATION forming part of Letters Patent No. 226,386, dated April 13, 1880.

i Application filed J unc 1875).

To all whom it may concern:

Be it known that I, ARTHUR E. BRIGGS, of Cincinnati, in the county of Hamilton and State ot' Ohio, have invented a certain new and useful Improvement in Magneto-Engines; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a perspective view of a magnetoengine, showing my improvements. Fig. 2 is a longitudinal section through the cylinder of the engine. Fig. 3 is a perspective view of one 0i' the east-iron sides ot' the cylinder, and Fig. 4 is a top-plan View of the cylinder with theV magnets removed.

Similar letters of reference in the several tigures denote the same parts.

My invention relates to the manufacture and use of n'iagneto-engines or electric generators of that class in which a cylinder is employed located between the two poles of a magnet and containing a revolving arma-ture and coil, by which the current is generated and transmitted; and it has for its object to improve the construction of the cylinder and cheapen the cost of its production, as I will now proceed to describe.

In the accompanying drawings, A represen ts the cylinder, B, the armature and coil therein; and CC,two magnets of thehorseshoe pattern, which embrace the cylinder between their poles and are clamped to each other by the bolt D and blocks E E.

The cylinder in this class of electric generators is composed of two cast-iron plates, Cr G, at the upper and lower sides bearing against the magnets, and of two brass plates, H H, interposed between the cast-iron plates, to which they are secured.

It has heretofore been the custom to cast the iron and brass plates separately and then rivet or screw them together, the contact-surfaces being first tiled down or milled to insure the necessary bearings and an accurate tit. This construction is objectionable and defective, because 0f the expense and labor attending the working and fitting of the plates, and because they cannot be so securely fastened together as to prevent them from workin g loose after the generator has been in use fora consideiable length of time.

To overcome these objections and defects I first cast the upper and lower iron plates in the form shown in Fig. 3, with dovetail recesses t' t' in each outer edge and a iiat outer surface to bear against the permanent magnets. Two of these plates are cast for a cylinder; and are secured togetherin the following manner: One plate is lirst placed in the sand, with the concave side uppermost. A core is then laid upon the upper side, and the top plate laid upon the core. The molten brass is then poured into the mold, filling the spaces between the two plates and entering the dovetail recesses i to form dovetail keys. As the brass cools its contraction is greater than the iron, and the result is, that the dovetail keys are drawn iirmly into the dovetail spaces, and aseeure and permanent lock is produced, as shown in the drawings, without milling, iling, or otherwise preparing the plates to produce a perfect Iit. To inish the cylinder thus formed it is only necessary to bore it out accurately to receive the armature.

The projecting ends K K of the iron plates shown in Fig. 3 are employed merely to snstain t-he plates in the sand, and are removed when the casting of the cylinder is completed.

The generator is usually applied to use, particularly for telephone lines, by placing it within a box, and the armature is rotated by a grooved pulley, L, on its projecting end, driven by a larger pulley, M, mounted upon a crank-shaft, N, whose bearings are in the side of the box, and a projecting arm, O, forming part of the brass casting, and extending between the two magnets. The crank is arranged outside of the box in the usual manner, and the large pulley carries a rubber rin g, I?, around its periphery, to tit into the groove of the armature-pulley L.

The rubber ring may be in the form ot' atlat band or around cord stretched into the grooved edge ot' the pulley, as shown, for the purpose of producing the necessary friction to rotate the armature when the crank is turned.

The constant or frequent use ofthe generator causes the rubber rin g to wear away, and therefore reduce the friction to such an extent as to IOO prevent the transmission of motion from one pulley to the other; and to overcome this defeet I make the large or drivin g pulley adjustable, to compensate for the wear ofthe ring, by employing an adjustable bearing for the crankshaft. This bearing is composed ot' a tube, R, having a plate, S, east upon its outer end, and is extended through a slot in the arm 0, between the magnets, so that the plate S shall l bear against the outer side of the arm, where it is held by the screws T. The ends of the plate are slotted for the passage of the screws, and therefore when the screws are loosened the plate can be adjusted on the arm to move the drivingpulley nearer to or farther from the armature-pulley, for the purpose above stated. The generator may be secured within its box by passing screws through the end of the latter into the outer face of the cylinder at the points u u, and by a screw through the bottom ot the box entering one of the clamping-blocks E, which rests upon the bottom. Any other convenient mode may be employed, however, for securely fastening the generator in place.

Havin g thus described my invention, I claim as newl. The mode of constructing the cylinder oi ARTHUR E. BRlGGS.

Witnesses:

E. A. ELLswoR'rIi, W. BL/rcKsrocK. 

